Display devices containing fluids which can be switched between different fluid configurations to provide different optical characteristics are known.
International patent application WO 03/071346 describes such a display device. A movement of the fluids during switching is controlled by using an insulating layer having a particular shape to modify an electric field applied to the fluids. A special electrode structure or an inhomogeneous oil fluid layer may be used alternatively to control the fluid motion.
International patent application WO 2006/021912 describes a device having picture elements which have a shape that determines, upon switching, a preferred direction of movement of fluids within the picture elements.
International patent application WO 2004/104671 describes an optical switch containing fluids which are switchable by application of a voltage across the fluids. An electrode used to apply the voltage has a shape which determines a preferred direction of movement of the fluids upon switching.
It is an object of the present invention to provide an optical apparatus with movable fluids which may be moved in a simple and controlled manner.